Really!
I'm going to give some examples and I want you to imagine that the offender is a woman in all cases. I say this because if it was a man, it might make sense, for personal safety, not to intervene but even then, I hope you would seek help.
Anyway, here goes with our offending woman whose actions do not have any effect on your own life.
Would you chastise or intervene if you saw someone in the car next to you emptying the rubbish from their car onto the ground?
Would you chastise or intervene if you saw a dog locked in a car with closed windows in a heatwave?
Would you chastise or intervene if you saw a cyclist riding on a pavement and knocking over an old person?
Would you chastise or intervene if you saw a teenagers playing roughly on park equipment designed for tots?
Would you chastise or intervene if someone had a shit on the pavement?
Would you chastise intervene if someone racially abused a stranger sitting next to you on the bus?
Would you chastise or intervene if you saw someone spit on fresh produce in the supermarket?
Would you chastise or intervene if you saw a man hit a woman?
Would you take charge of a three year old who was clearly lost?
If we all took your attitude-nothing to do wiv me mate-society will soon fall apart at a faster rate then it is already doing.
Your attitude is nothing to boast about because one day, someone will do something morally or criminally wrong that does affect you and no-one will come to help.
OP. You did exactly the right thing.
Hopefully you shamed this shameless woman because it is about time that shame and judgement became forces that helped to keep those, who cannot discipline themselves, in check.
Well done!